The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Internal combustion engines combust air/fuel charges in combustion chambers to generate work. Combustion of an air/fuel charge is dependent upon the temperature and pressure conditions existing within the combustion chamber. Variations in temperature and pressure within the combustion chamber affect combustion and associated work and emissions that are generated thereby.
Exhaust gas recirculation (EGR) systems recirculate exhaust gas into an intake system to mix with the air/fuel charge and affect combustion. This includes reducing combustion temperature, thus reducing generation of NOx species and emissions. EGR systems are used in different engine types and configurations, including both compression-ignition and spark-ignition engine systems.
The temperature of the recirculated exhaust gas affects the temperature of the air/fuel charge within the combustion chamber. Known EGR systems may include a heat exchange device in the EGR system to modulate the temperature of recirculated exhaust gas, and thus modulate the temperature of the air/fuel charge. Known EGR heat exchange devices can remove heat and thereby reduce temperature of the recirculated exhaust gas. Known heat exchange devices conductively transfer thermal energy between the recirculated exhaust gas and a coolant, and/or radiantly dissipate thermal energy through physical devices, e.g., fins exposed to ambient air. Heat energy thus transferred may be lost.